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Discussion Starter · #1 ·
Hey guys,

New here, but I had a bit of an odd question about a bandsaw I just picked up off of craigslist. It's a Sheng Tsai 14", which I've been told is just a Delta with different branding. In any case, It was running a bit rough so I decided to do a full breakdown; oil all the bearings, etc. When I opened up the belt housing I noticed three belts, one coming from the engine, but two going to the saw wheel. The two going through the saw wheel have two different radii where they come off the driver, but the same radii where they are attached to the saw wheel, which would suggest to me that they have to be turning at different speeds. It seems to run ok, but it definitely requires quite a bit of strength to turn the saw wheels, and it sqeeks a fair bit when I turn it. So did the previous owner simply put the two belts on for storage? Or does it come like that and you're supposed to remove one? Or is it fine the way it is? I've attached some pictures since I'm sure my description was hard to understand. Any advice would be appreciated, thanks!

Jonathon
 

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where's my table saw?
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there should be one belt

There is a step pulley on the lower from the motor drive that has 4 places for a V belt. Chances are you can only use 2 of them because the belt will be at a skewed angle. The driven pulley to the saw wheel only has two V grooves as far as I can tell, but you can only use one belt. Two belts will be fighting each other over speed. Putting the belt on the smaller step will reduce the speed, the larger step will increase the speed of the blade.
For woodcutting run the faster speed.
 

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I would suspect the step pulley is made to where you could adjust it in or out or turn it around to be able to set the band saw up to run at different speeds. You would use the slowest speed to cut steel with it, a midrange to cut brass or aluminum and the fastest speed to cut wood. I believe you should only have one belt going up to the drive wheel on the saw. I think the two pulleys on the drive wheel is there for quick change for two different speeds.
 

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A simple reply - You have one too many belts on there. Only one belt should be on the pulleys. Woodnthings is right -- the belts are fighting each other.

I wonder if someone swapped out the smaller diameter pulley with one from a drill press or something. Since the big pulley has two grooves, the small one only needs two grooves.

Looking at your pictures some more, it appears that the pig pulley has two sheaves of the same diameter. This would require that a different length pulley be used for the different size sheaves on the small pulley for a speed change. Maybe the original owner knew this and has a belt on there for each of the two speeds, but the one is loose - and squealing. Just take the one belt off that isn't needed for whatever speed you want to run (probably the faster speed for wood). Keep the other belt around if you wish to change speeds in the future.

Bill
 

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where's my table saw?
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Bill, have 1 more cup of coffee...

A simple reply - You have one too many belts on there. Only one belt should be on the pulleys. Woodnthings is right -- the belts are fighting each other.

I wonder if someone swapped out the smaller diameter pulley with one from a drill press or something. Since the big pulley has two grooves, the small one only needs two grooves.

Looking at your pictures some more, it appears that the (big) pig pulley has two sheaves of the same diameter. This would require that a different length (belt) pulley be used for the different size sheaves on the small pulley for a speed change. Maybe the original owner knew this and has a belt on there for each of the two speeds, but the one is loose - and squealing. Just take the one belt off that isn't needed for whatever speed you want to run (probably the faster speed for wood). Keep the other belt around if you wish to change speeds in the future.

Bill
Allow me to make 2 corrections for Ya. ;)
 

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Discussion Starter · #6 ·
Hey guys,

Thanks a ton for the advice, I took off the smaller belt (i.e. the slower one) and she runs like a charm. Still pretty darn confused about why anyone would ever have put two belts on there, but oh well. Thanks again!

Jonathon
 

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I hadn't used my 14" Sheng Tsai Bansaw for awhile and now the blade just runs off the pulleys. Is this just a worn out blade or is there a way to adjust it? Any help would be appreciated.
 

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where's my table saw?
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It could be either of these ......

First, unplug the machine.


All bandsws have a blade tracking adjustment knob behind the upper wheel. If I recall correctly, turning the knob CW will make the wheel tilt to the rear at the top which makes the blade track to the rear of the wheel ...AS YOU SPIN IT BY HAND! Turning it opposite or CCW, will have the opposite effect. I may haveit backwards as far as the rotation .... I donno?


Another issue may be the blade has taken a warp. See if it will lay flat on a known flat surface, like a granite countertop. The weld may have opened up causing it to track off the wheels. The rubber tires may have developed a flat from the blade being under tension on them for a long period. Spin the wheels be hand while watching the tires to se eif there is any deviation from running true. there are replacement tires on Ebay and instructional videos on You Tube to install them.


The bottom wheel may have come loose. See if the wheel can be move by hand in or out. There is a keyway and square key on the shaft held on with a set screw which may be loose. Use the correct Allen key to tighten it.

Reinstall the blade but back away all the side guides and backup guides/thrust bearings. see if the blade will track on the center of the tires and use the tracking adjustment to center it. If the blade is OK, reinstall it by lowering the upper wheel, then raise it and tension it so it can be pushed gently sideways only about 1/8" with one finger when the guides are fully raised up. I pluck mine and listen for a certain sound it makes that I know is the right amount of tension. I can't tell you here what that sound is .....
Then turn the machine on after you close up the blade covers and see if the blade will stay on.

That should cover all the issues I know of. :vs_cool:
 

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The bottom pulley is likely wrong, added afterwards to give some variability for speed. You should try to find the original drive pulley, it will have two grooves and the engineer designed it that way for power. With only one belt in use you may find the saw slips when cutting thick or hard wood. Maybe that's not a concern for your application but if it is then the double groove drive pulley will enable more of the motors tourque and power to be transferred to the saw blade. Don't spend ten years wondering why it feels underpowered LOL.
 
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